Page 146 - Wonderful Creatures: Children! Have You Ever Thought ?

WONDERFUL CREATURES

THE STRUCTURE OF

BIRDS’ FEATHERS

The most important differen-
ce that distinguishes birds

from other creatures is surely
their ability to fly. Birds can fly

by means of their feathers, which
in fact have a very special structure.

A bird feather is a light structure that
has lift force and can easily regain its
original shape. If we examine a bird's

feather under a microscope, we see a

marvelous creation. In the middle part of
the feather is a hard central shaft with a series of paired branches
called barbs on either side. These barbs, whose lengths and soft-

ness vary, enable the bird to fly in the air.

As we examine the subject in further detail, we encounter even

more interesting structures. Minute hairs called “barbules” project
from each barb. Barbules cannot be seen with the naked eye. On

these barbules are little hooks. The barbules are interlocked by
these hooks, just like a zipper.

The hooks are clamped together like the two rows of a zipper. The

barbules held together by hooks are so close to each other that
not even smoke can pass through them. If these hooks are some-

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